client/webpack.config.js

'use strict'

import dotenv from 'dotenv'
dotenv.config({ path: resolve(import.meta.url, '..', '.env') })

import { resolve } from 'path'
import HtmlWebpackPlugin from 'html-webpack-plugin'

import { fileURLToPath } from 'url';
import { dirname } from 'path';
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const mode = process.env.NODE_ENV || 'development'

let entry = [resolve(__dirname, 'src', 'index.js')]
let plugins = [new HtmlWebpackPlugin({
    template: resolve(__dirname, 'src', 'index.ejs')
})]
let devtool = undefined
let babelLoaderPlugins = ["@babel/plugin-transform-runtime"]

if (mode === 'development') {
    const webpack = (await import('webpack')).default
    const ReactRefreshWebpackPlugin = (await import('@pmmmwh/react-refresh-webpack-plugin')).default
    entry = ['webpack-hot-middleware/client', ...entry]
    plugins = [new webpack.HotModuleReplacementPlugin(), new ReactRefreshWebpackPlugin(), ...plugins]
    babelLoaderPlugins = [...babelLoaderPlugins, "react-refresh/babel"]
    devtool = 'inline-source-map'
}
console.log(`Webpack configured for ${mode}`)

export default {
    entry,
    output: {
        path: resolve(__dirname, 'dist'),
        filename: 'bundle.js',
        publicPath: '/'
    },
    devtool,
    mode,
    module: {
        rules: [
            {
                test: /\.jsx?/,
                resolve: {
                    fullySpecified: false
                },
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        plugins: babelLoaderPlugins,
                        presets: [
                            ['@babel/preset-env', {
                                useBuiltIns: 'entry',
                                corejs:{ version: "3.10", proposals: true },
                            }],
                            '@babel/preset-react']
                    }
                }
            },
            {
                test: /\.s[ac]ss$/i,
                use: ['style-loader', 'css-loader', 'sass-loader'],
            }
        ]
    },
    plugins
}